Kinetic, isotherm modeling analyses of the adsorption of phenol on activated carbon/alginate composites

NOVELTY STATEMENT Pyrolysis is among the disposal methods applied to reduce the impact of agricultural and animal wastes on the environment and human health and to ensure their management. Biochars are widely used alternative adsorbent for the removal of pollutants from wastewater. No published work has been on the walnut shell biochar (WSB) encapsulated alginate hydrogel bead for the phenol adsorption from an aqueous solution. The novelty of this study was to compare the adsorption capacity, and removal efficiencies of calcium alginate-commercial activated carbon composite beads (CA-AC) and calcium alginate-biochar composite beads (CA-WSB) prepared from walnut shells by pyrolysis and investigated the adsorption performance for phenol removal. The present study aimed to synthesize calcium alginate-commercial activated carbon composite beads (CA-AC) and calcium alginate-walnut shell biochar composite beads (CA-WSB) using activated carbon (AC), walnut shell biochar (WSB), and to apply its efficiency in phenol removal. The synthesized samples were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray fluorescence (XRF) spectrometry. The Brunauer, Emmett, and Teller (BET) method was used to obtain information about the samples' surface area and pore size. The kinetic model of phenol fitted well to the pseudo-second-order kinetic model. The isotherm model of phenol fitted well to the Langmuir isotherm model compared with other models. The maximum adsorption capacity was 76.92, 0.419, 8.130 1.375 mg/g for AC, WSB, CA-AC, CA-WSB.